Conventional construction vehicles (dozers, loaders, backhoes, skid steers, graders, etc) do not usually have cushioning suspension systems but are, at most, equipped with pneumatic tires. The consequence is that the machine ride can be very harsh dependant upon the operating conditions of the machine.
Traditionally blade equipped vehicles such as crawlers or graders are structurally rigid. This is desirable to avoid undesirable vertical blade movements under changing soil conditions. The cutting edge of the blade is, typically, angled back at the top so that it will shave off the material when elevated material is contacted. A consequence of this characteristic is that a vertical force is generated on the blade cutting edge when hard soil conditions are encountered. If the machine is not sufficiently rigid, the blade will lower and dig into the ground under these conditions. When soft soil is encountered and the vertical force reduced, the blade will tend to rise to a higher elevation.
An analogy can be made to a plane that is used in woodworking. A rigid plane would tend to shave off high regions without gouging, and move over low regions without any affect to the material. A relatively flexible plane would tend to gouge the high regions of the wood surface.
The addition of suspension to construction vehicles such as, for example, crawlers and graders, can create a situation that is counter to the desired operating conditions stated above.